Energy efficiency is a popular concept in the modern era, especially among people who are conscious of environmental issues. Reducing energy consumption in computer networks brings about many benefits, the least of which including reducing operation costs and saving energy and thus the environment.
To ensure performance quality, computer networks, especially large networks such as those associated with data centers or large institutions, often include a great number of routers and contain a high amount of coupling and redundancy between these routers in order to provide fast data transfer and recovery rates. Consequently, the largest energy consumption in a computer network is often in the individual routers, such as the energy required to maintain, process, and operate each router. In comparison, the energy required to actually transfer data over a computer network is relatively insignificant.
Network usage typically varies depending on the time of the day or the day of the week. For example, at nights or on weekends, network usage is often low because less people are working. And yet, the routers are kept running at all hours and thus consume large amounts of energy even when their usage is low. Energy is needlessly wasted as a result.